The Ecumenical Patriarchate of Constantinople has agreed to recognize the independence of the Ukrainian Orthodox Church, a move immediately hailed by Ukrainian President Petro Poroshenko but slammed as 'catastrophic' by Moscow.

A synod meeting in Istanbul chaired by Patriarch Bartholomew I, who is considered the leader of the 300-million-strong worldwide Orthodox community, or 'first among equals' of Eastern Orthodox clerics, decided on October 11 to 'proceed to the granting of autocephaly' to the Orthodox Church of the Kyiv Patriarchate.

The synod, however, made sure to warn against violence and attempted property takeovers.

The move, which comes amid a deepening row in Orthodox Christianity over the Ukrainian Church's bid to formally break away from Russia's orbit, was hailed by President Petro Poroshenko as 'something that we have dreamed of, waited for a long time, and fought for all the time.'

But the Russian Orthodox Church condemned the decision as 'catastrophic.'

'Today the Patriarchate of Constantinople has made catastrophic decisions -- first and foremost regarding itself and global Orthodoxy,' a spokesman for Russian Orthodox Patriarch Kirill, Aleksandr Volkov, said in televised remarks. 'The Patriarchate of Constantinople has crossed a red line.'

Earlier, Kirill was quoted as saying that his church will 'have to break eucharistical relations with Constantinople' following the decision.

SEE ALSO: Broken Faith: Ukrainian Church Fights For Independence From Moscow

Ukraine currently has three Orthodox denominations: the Ukrainian Orthodox Church of the Moscow Patriarchate, which remained subordinate to Russia after the breakup of the Soviet Union; and two breakaway entities -- the now-recognized Ukrainian Orthodox Church of the Kyiv Patriarchate, and the Ukrainian Autocephalous Orthodox Church.

The three are nearly indistinguishable in terms of their rituals but differ when it comes to the issue of church independence. And, along with the Russian church, they each trace their history to the ancient medieval state of Rus in Kyiv.

The Kyiv Patriarchate is headed by 89-year-old Patriarch Filaret, who was once a front-runner to head the Russian Orthodox church. Filaret, who was excommunicated as Ukraine gained independence from the Soviet Union and he pushed for an independent Ukrainian church was reinstated, together with Kyiv Metropolitan Makariy to their canonical ranks, in another key move by the synod.

'Thus, the above-mentioned have been canonically reinstated to their hierarchical or priestly rank,' said the statement.

Obtaining the long-sought-after independence -- or autocephaly -- of the Kyiv Patriarchate marks a significant triumph for Poroshenko and his reelection hopes in March 2019.

Patriarch Filaret of the Ukrainian Orthodox Church of Kyiv (file photo)

'The decision made by the Ecumenical Patriarch and the synod has definitively dispelled Moscow's imperial delusions and chauvinist fantasies -- which had no support in any church-law documents -- on Ukraine as an allegedly canonical territory of the Russian [Orthodox] Church,' Poroshenko said in a televised address.

There are concerns that the move could stoke tension and violence.

The Kyiv Patriarchate has already laid claim to the famous 11th century Kyiv Monastery of the Caves or the monastery in Pochayiv. Both are in the hands of the Russian-dominated Ukrainian Orthodox Church.

That is probably why Bartholomew appealed to all sides involved 'that they avoid appropriation of Churches, Monasteries and other properties, as well as every other act of violence and retaliation, so that the peace and love of Christ may prevail,' according to the statement.

The Ecumenical Patriarch, currently Bartholomew I, also holds the title of archbishop of Constantinople, the old Greek name for Istanbul, Turkey's largest city. The city fell to the Muslim Turks in 1453 but has remained the historic seat of Christian Orthodoxy.